Voltage regulator



Jul'y- 2l, 1931 Q B CROUSE 1,815,141

VOLTAGE REGULATOR Filed Deo. 14,'"1926 Patented July 21, 1931 UNITED STATE GEORGE B. CROUSE, 0F WOODCLIFF, NEW

JERSEY, ASSIG-NOR TO CGNNER CROUSE COR- PORATION, OF NEW YORK, N. Y.,

A CORPORATION OF NEW YORK VOLTAGE REGULATOR Application led December 14, 1926.

This invention relates to voltage regulators, and more specifically to voltage regulators for compensating for' temperature caused changes of resistance in the transmission circuit elements of an electrical system.

In an electrical system comprising` a source of energy, a load and intermediate transmitting or converting elements such as transformers, rectifiers and/or lters, the current passing through these elements will cause their temperature, and thus their resistance, to rise. Unless the elements are made uueconomically large, this increase of resistance will cause a troublesome drop of potential at the output of the system.

An object of this invention is to provide apparatus for compensating for the eiiect of temperature caused variations of the output voltage of an electrical system. A further object is to provide apparatus for the purpose stated which shall be economical of first cost and electrical energy. More specifically, an object is to provide apparatus for filtering alternating current components from a direct current supply and in which variations in the temperature of the filter elements will not effect a variation of the load voltage.

These and other objects of the invention will be apparent from the following specification, when taken with the accompanying drawings, in which Figs. l, 2 and 3 are diagrams of electrical converter and filter circuits in which the invention is embodied.

Referring to the drawings, Figs. l and 2 are diagrams showing the application of the invention to electrical converters and filters.

In Fig. l, the terminals of an alternating current supply are shown at l and 2, feeding energy to a converter 3. The direct current out-put of the converter is passed to a load 4 through a filter comprising the series coils 5 and 6 on the iron cores I'iand 8, and the shunt resistance 9. This system is a well known combination and requires no special explanation. The alternating current supplied by the source is changed to Serial No. 154,790.

pulsating unidirectional current by the converter 3, and the pulsations of the converter are removed by the filter, so that substantially smooth direct current is delivered to the load.

Assuming that the system has been out of operation for such time that the parts are ail at the temperature of the ambient air, the placing' of the system into operation is followed by a gradual increase in the temperature of the parts. rlhe rise of temperature of those windings which are in effective series relation between the source and the load will cause a corresponding diminution of the voltage across the load, due to the temperature-resistance coeflicient of the windings.

To prevent this diop of load Voltage, the shunt element 9 is formed of material having a high or positive temperature coefficient, and is so proportioned in thermal and electrical characteristics, in relation to the other elements of the system, that, as the temperature of the system rises, the amount of the current by-passed through 9 diminishes. In this manner, the total current, i. e. the load current plus the current through 9, will diminish so that the potential drop across those elements in series relation between the source and the cross resistance 9 will be diminished by the amount that the drop across the series elements between the resistance 9 and the load has increased, so that the voltage across the load remains substantially constant.

The same regulation of the load voltage may be effected without modifying the construction or operation of the filter system. The converter, load and filter elements of the circuit of Fig. 2 may be substantially identical with the respective elements of Fig. l which are identified by the corresponding numerals l to 8, inclusive. In place, however, of the temperature-variant resistance 9 of Fig. l, the shunt element 9 of the filter may be of the usual construction, i. e. of substantially constant value. rlhe circuit includes the temperature-variant resistance l0 which is connected directly across the load 4:. In this circuit the reliti@ sistance 10 should be so proportioned that the product oil' the total current flowing through the elements in effective series relation between the source and the load times the resistance o t' those elements, will remain substantially constant.

ln Fig. 8, the invenion is shown applied to the filter system shown in my co-pending application No. 130,252, filed August 1S), 192". ln tiis circuit, as betere, the terminals l, 2 of an alternating current supply deliver energy through the converter 3 to the direct current load 4. .lnductances 11, 12, 13 and 111, ivound on iron cores 15, 16, 17 and 18, respectively, are arranged as series elements in one et the load lines. resistance 18 is shunted across the inductance 12, and a second resistance 1) is connected across the inductances 13, 14h and the load 4l.. rlhe operation ot this arrangement as a ilter is fully described in the application above mentioned..

rlhe resistance 19 is formed oit material having such teinperat 1re-variant properties that it may function in the same manner as the resistance 9 ot the lilter shown in Fig. 1.

It Will be ae/parent Lhat tor the compensation to be ellective all times, the tenr peinture-time characteristic oli the controlling resistance 9, 10 or 19, must be the s@ ne as that ot the series elements. rl`he actual design of the resistance to secure this result can only be determined by experiment. lt may be pointed out hovcever that only three factors ai'lwcct the design, irst, the normal energy dissipated in the control resistance; second, its thermal capacity, i. e. specilic heat times mass; and third, its thermal insulation. rlhe amount of enerey converted into hea-t in the resistance will normally be iiied by other considerations, and therefore it Will only be necessary to vary the size of the unit and character or thiol:- ness of its covering material.

lllhen very exact compensation is desired, the controlling resistance may be arranged to be in thermal contact with any or all ot t-he series elements ol' the system.

lt will be apparent that the invention is not limited to the specilic circuits shown in the accompanying drawings, but is useful in electrical circuits in which temperaturevariant transmitting elements are located between a source ot energy and the load. lt is therefore to be understood that the various elements, the'r relative size and arrangement, are subject to Wide variation Wit-hout departure from the spirit of my invention as set forth in the following claims.

l claim:

1. In an electrical system, the combination with a source et energy, a load, and a series transmission element therebetween having a positive temperature coetlicient, ot a resistance across said load having a positive temperature coefficient, said resistance being arranged in heat-transfer relation with said series element and so proportioned that its temperature-produced variation ot resistance substantially neutralizces the etl'ect upon the load voltage ot the current-produced change of resistance of said element.

Bln electrical ilter comprising a plurality et series inductances and a resistance shunted aerei-s the line between said inductances, said resistance having a positive temperature coefficient and a temperature-tin'ie characteristic such that current-produced changes in the temperature ol' the elements ot said filter render the output voltage of the filter substantially independent ot the temperature oil the elements.

ln testimony whereof, l allii: my signature.

GEORG-E B. CROUSE. 

